Finding the Fourth Proportional to 1,112.78, 1,535.61 and 615.44

Step by Step Solution

1. Step 1: Write the proportion equation
   1,112.78 : 1,535.61 = 615.44 : x
2. Step 2: Convert to fraction form
   1,112.78/1,535.61 = 615.44/x
3. Step 3: Cross multiply
   1,112.78x = 1,535.61 × 615.44
4. Step 4: Simplify right side
   1,112.78x = 945,075.82
5. Step 5: Solve for x
   x = 945,075.82/1,112.78
6. Step 6: Final answer
   x = 849.29